SU1740758A1 - Method and device for diagnosis of fuel equipment of diesel engines - Google Patents

Abstract

The invention relates to engine-making, namely to tests of fuel-spraying equipment and allows to increase the accuracy of testing of diesel equipment. In the motorless test of diesel fuel equipment, the current angular speed of the drive shaft (PV) of the test bench without a high pressure pump (Injection pump) within one revolution per series of consecutive revolutions is additionally measured, the current angular speed of rotation of the drive shaft of the test bench with the injection pump in the same limits at that the average angular velocity of rotation of the drive shaft, the maximum and minimum value of the change in the current angular velocity introduced by the injection pump is determined in each cycle of the injection pump operation, and the state pparatury with the dispersion of those values. A device for implementing the method is equipped with a switch 11 serving to distribute measurement information to the corresponding inputs of the buffer storage device 12 according to a signal from the drive shaft load sensor 22, a synchronizer 13 connected in communication between the storage device 12 and the selection logic 14 of a change in the current angular velocity rotation of the PV, made by the actual pump, selectors 16 and 17 of the maximum and minimum values of angular velocity, as well as serially connected valve 18, etnym unit 19 and gauge 20 dispersion extreme values varying rotational angular velocity MF, insertion of fuel pump, the signal is judged which state of the apparatus. 2 sec. f-ly, 4 ill. sl c VI .N o VJ cl 00

Description

The invention relates to the testing of machines and engines, namely high pressure fuel pumps and engine injectors.

The aim of the invention is to increase the reliability of diagnosing fuel equipment.

FIG. 1 shows the experimental curve and the change in the current angular velocity of rotation of the drive shaft of the stand

without a high-pressure fuel pump (high pressure pump) for a series of consecutive rotations, experimental curve b for changing the current angular speed of the drive shaft (PV) of the test bench when testing a high pressure pump for a series of consecutive revolutions, straight in - average value of the angular velocity of rotation of the drive shaft supported by an angular speed stabilizer , curve r pulses cam

shaft; in fig. 2 - highlighted curve of change in the current angular speed of the drive shaft of the stand, introduced by the pump, and curve of the pulses of the boundaries of the work cycles of the pump; in fig. 3 is a block diagram of a stand for carrying out the proposed method; in fig. 4 is a timing diagram of the principle of measuring the time intervals of the rotation of the vertical position at each angle equal to the angular pitch of the teeth of the generator of the angular velocity of rotation of the vertical axis.

In the drawings indicated:

ft) is the current angular rotation speed of the drive shaft;

p ° in - angle of rotation of the drive shaft of the stand;

 - change of the current angular speed of rotation of the drive shaft of the stand without the pump;

& and - change the current angular velocity of rotation of the drive shaft of the stand with the pump;

UCP is the average value of the angular velocity of rotation of the drive shaft, supported by the angular velocity stabilizer;

c # tn highlighted the change in the current angular velocity of rotation of the drive shaft of the stand, made by the pump;

max and (respectively, the maximum and minimum values of the selected current angular velocity of rotation of the drive shaft of the stand in the i-th operating cycle of the high-pressure pump.

The duty cycle of the high pressure pump means the angle of rotation of the camshaft over the period of change in the total moment of resistance.

Aod - the amount of decay of the selected current angular velocity of rotation of the drive shaft of the stand in the i-th operating cycle

Fuel pump (Aft, uWc i

And - the boundaries of the cycle with the injection of fuel injection nozzle;

Da - voltage pulses produced by the reference frequency generator delivered to the second input

encoder counter;

Up - voltage pulses generated by the sensor of rotation angle PV from each angular mark of the setpoint angular velocity of rotation of the drive shaft;

UHO voltage pulse generated by the origin sensor, only on the arrival of which the input of the measured information to the memory device begins;

NI, .... NJ is the number of pulses of voltage Us, counted by the encoder counter, in the time interval between each

0

neighboring voltage pulses IR / stored in the corresponding memory register of the memory;

YV-angle of rotation of the drive shaft. A device for implementing the test method contains a drive engine 1, a stabilizer 2 of average angular velocity of rotation of the drive shaft (PV) of the stand, a sensor 3 of the current angular velocity of rotation of the PV rigidly mounted on the PV of the stand, rotating the camshaft 4TNVD connected to the device 5 for determining medium cycle feeds, the sensor 6 of the angle of rotation of the shaft connected through the amplifier converter 7 to the input of the counter 8, the second input of which is connected to the output of the generator 9 of the reference frequency, and the output to the key 10, the switch 11 connected Connected by its input with the output of the key 10, and output with the corresponding inputs of the buffer storage device 12, the synchronizer 13, connected to the connection between the buffer storage device 12 and the allocation unit 14 connected with the storage device 15 and the selector 16 of the maximum and the selector 17 of the minimum angular velocity of rotation of the PV, as well as with the distributor 18, the counting unit 19, to the output of which connect the dispersion meter 20, the reference sensor 21 connected to the key 10, the load sensor 22 connected to the second input the switch 11, and the end of count sensor 23 associated with the third input

5 switch 11 and the valve 18 extreme values.

The device works as follows.

When the drive shaft rotates, set 0

3, rigidly fixed to the drive0

The shaft of the PV stand, in the angle sensor 6, voltage pulses are induced, the frequency of which is proportional to the current value of the angular velocity of the PV rotation. The pulses from the booster shaft rotation sensor are fed to a converter amplifier 7, which forms rectangular voltage pulses. These pulses are the main operating pulses, the time intervals of which are directly determined by the measuring system. The rectangular voltage pulses from the output of the amplifier - converter 7 are fed to the control input of the counter 8, which counts the number of high-frequency memory pulses produced by a highly stable reference generator during each time between adjacent working pulses

frequencies 9. The counted number of storage pulses, encoded in a digital binary code, is fed to the key 10. To ensure synchronization of the measured values of the current angular velocity of rotation of the PV along its angle of rotation, the key 10 always starts to pass the measured information to the input of the switch 11 only when the enabling signal arrives pulse to your second input of sensor 21 of origin. The graphically described principle of obtaining initial information is illustrated in FIG. 4. Switch 11 serves to distribute the measured information according to the information inputs of the buffer memory 12, depending on the signal from the load sensor 22, which determines the test mode (without injection pump, with the injection pump). In addition, by the signal of the sensor of the end of the countdown 23, the switch 11 marks the limits of the duty cycles of the high pressure pump.

In the test mode without a pump, the switch 11 directs a given sample of measured information translated by multiplying by a constant factor into units of angular velocity (i.e. instantaneous angular velocity values of the rotational velocity of the actuator during the rotation of the actuator by the angle of follower of the indicator angles 3), In the first group of memory registers of the buffer memory 12. When testing a pump in the same control mode, the switch 11 sends instantaneous values of the angular velocity of rotation of the PV to the second group of memory registers of the buffer memory inayuschego device 12. Accordingly, the outputs of the buffer memory 12 to the information supplied to the inputs of the synchronizer 13 and then to the extracting unit 14, adapted to release varying the current rotational angular velocity MF, proper insertion pump. Further, the selected instantaneous values are fed to the storage device 15 and are sequentially stored in memory registers with increasing address numbering. Then, the information allocated by the allocation unit 14 and the information placed in the memory 15 is fed to a selector 16 of maximum values of angular velocity and to a selector 17 of minimum values of angular velocity of rotation PV. The thus obtained extreme values of the angular velocity of rotation of the PV in each operating cycle of the injection pump to the installed series of consecutive cycles arrive at the distributor 18, designed to distribute the measured information to each section of the injection pump separately. With distributor 18

of extreme values of the information is fed to the counting unit 19, designed to determine the magnitude of the decrease in the angular velocity of rotation of the PV for the working

the injection pump cycle for a series of consecutive cycles, and further to the dispersion meter 20 to determine the dispersion of the obtained values of the decrease in the angular velocity of rotation of the PV for a series of consecutive cycles as

0 for the pump as a whole, and for a series of consecutive cycles for each section separately.

In addition, when testing the injection pump nozzle inject fuel into the device

Claims (2)

5 to determine the harmful cyclic feeds in individual sections and on the technical state of the fuel equipment are judged by the totality of the measured parameters. Invention Formula 0 1. A method for diagnosing diesel engine fuel equipment, which means that at a given amount of fuel supply the cam shaft of a high pressure pump rotates at a given angular velocity, the current angular velocity in each cycle is measured, and the dispersion of the parameter characterizing the angular velocity variations is determined for each section of the pump, and the largest dispersion judge the state 0 fuel equipment, characterized in that, in order to increase the reliability of diagnostics, the fuel supply is shut off by a high-pressure pump and as a parameter characterizing 5, the change in the angular velocity in each cycle measures the maximum and minimum values of the change in the current angular velocity as the feed amount changes from the set point to zero. 0 2. A device for diagnosing fuel equipment of diesel engines, containing in series connected shaft angle sensor, amplifier-converter, counter with counting and control 5 inputs, a key with information and control inputs, as well as a maximum and minimum value selector associated with its input with a key output, a dispersion meter, a distributor, 0 whose input is connected to the output of the selector, a reference frequency generator, the output of which is connected to the control input of the counter, and a reference sensor connected by its output to the control input of the key, characterized in that, in order to increase the reliability of the results The device is equipped with a switch with three inputs, a buffer storage device, a synchronizer, an allocation unit, and a storage device, as well as a load sensor, a reference sensor and a counting unit, the first input of the switch is connected to the output of the key, the second to the load sensor, and the third to the sensor of the end of reference, the distributor is made with an additional Have the input connected to the output of the sensor of the end of the countdown, the output of the memory device is connected to the input of the selector, while the counting unit is connected by its input to the output of the distributor, and the output to the input of the dispersion meter and t & Wtp.} L -V v-vFig. 2